TL;DR: Eurostars is the Eureka programme that funds R&D projects run by innovative SMEs together with at least one partner in another country, co-funded by the EU through Horizon Europe. The next deadline is Call 12 on 4 March 2027 (opens 17 December 2026). There is no single Eurostars grant: each partner is paid by its own national agency, typically 50–60% of R&D costs for an SME, with caps such as €500,000 for the Dutch share or €360,000 per project in the UK. It is worth it if you already have a real partner abroad and can co-fund the rest; it is a poor fit if you are looking for a partner just to qualify. Below: a timeline, a fit worksheet, a budget table, a worked example and a copyable partner email.